robert wagner is not the one to answer from police. jenna: we'll watch this mystery and. harris, thank you. >> reporter: sure. jon: a subway attack caught on tape. where this terrifying scene unfolded. what police are saying about the suspect in the video. >>> also a brain scan, it's an old tool but now doctors have found a new way to use it and it could be very helpful to our troops, suffering from ptsd. and those who suffer from conditions like depression. i will have that story for you coming up. jon: "happening now", a legal victory for an iraq war veteran suing the veterans administration. this marine vet and his wife sued back in 2010. he claimed doctors were grossly negligent in treating his post-traumatic stress disorder or ptsd, saying as a result his symptoms got worse, leaving him disabled an unable to work. well a federal judge awarding the vet $3.7 million for lost wages and pain and suffering as a result. >>> the scars of ptsd may be invisible but all too real for the brave men and women who feel its impact every day. now doctors are researching a promising